lunes, 22 de noviembre de 2010

4ta publicacion. nanyoly mendez. CAF. 1er parcial

MEMS and Microsystems in Europe

The term MEMS (micro-electro mechanical systems) is heard frequently in Europe, but most of the organizations our group visited prefer "microsystems" (or the acronym MST — microsystems technology) to define the domain of interest. MST has a significantly broader meaning than MEMS. While devices fabricated with IC technology that include moving or moveable parts for actuation or sensing are of course included, so are other categories of very compact device types where shape is critical to functionality, including both passive and active devices. The field of MST also includes work that seeks to incorporate such devices into highly compact systems.1

A useful operative definition of the scope of MST as understood in Europe was developed by a NEXUS task force in 1998 (see below for a brief description of NEXUS):

"Microstructure products have structures in the micron range and have their technical function provided by the shape of the microstructure. Microsystems combine several microcomponents, optimized as an entire system, to provide one or several specific functions, in many cases including microelectronics."

As evidenced by this definition, microsystems in Europe do not necessarily include integrated circuits, nor are they always monolithically integrated. As this report will show, the European technical community envisions numerous types and varieties of devices and applications for future microsystems in Europe, making them a pervasive influence in many product sectors ranging from automotive and domestic electronics to the medical and pharmaceutical sector.MEMS and Microsystems in Europe.

MEMS/Microsystems Device and Process Technologies: The State of the Art
On a worldwide basis, MEMS devices or microsystems which have successfully established high-volume commercial markets include accelerometers and pressure sensors for automotive applications, inkjet print heads, and digital micro-mirrors for image projection. The automotive MEMS supplier group has strong European representation by companies such as Bosch, TEMIC, SensoNor, and VTI-Hamlin, all of which are major players in this market. The other two device classes are mostly supplied by U.S. and Japanese companies.

In addition to major industry players, our team visited with research institutes, government laboratories, and universities pursuing new and emerging technologies and applications, in order to find out about the future of MEMS and microsystems in Europe.

* Among the institutions and companies the MCC team visited in central Western Europe (Germany, Switzerland, France, Belgium, and the Netherlands), the device classes being pursued mostly fell into the following categories:

Fluidic MEMS: The majority of sites visited had a significant level of effort in fluidic devices such as pneumatic valves, membrane pumps, chemical reactors, and flow and pressure sensors. The application targets range from medical and biological, to pharmaceutical and chemical. Miniaturization here increases portability, reduces cost, increases accuracy, reduces the amount of chemical or biological sample material required for analysis, and also decreases measurement time.

Mechanical Transducers: With major applications and markets already established in this device class, the work in the research and development laboratories we visited focuses on further integration for cost reduction, including work with side-impact sensors, or specialty application niches with less price pressure, ranging from instrumentation, aeronautics, and down-hole sensing for drilling equipment, to medical patient monitoring. Most of the sites we visited continue to work in this class of devices.

Optical MEMS: Some of the laboratories visited are working on micro-opto-electro-mechanical devices such as micromirrors for scanning or imaging applications, temperature IR sensors, as well as miniaturized devices such as connectors and switches for fiber applications.
Electrical MEMS Switches: Several European groups are competing in this area, with Siemens leading the way towards commercialization.

Others: Many of the laboratories visited presented work on passive miniaturized components without any moving part such as integrated inductors, magnetic devices, trench capacitors, ISFETs, etc.

Device technology areas where the MCC team did not see evidence of significant level of activity are fuel cells, micro-motors, and wireless communication (RF/microwave), although Europe is said to have a significant amount of activity in the RF/microwave area.

* The process and device technologies used in these efforts include all approaches and a variety of materials. The European microsystems researchers are pragmatic in the ways they approach miniaturization; they are not partisan to a particular process or technology but usually have a variety of process capabilities at their disposal, either internally or through collaboration within the European and national programs. They focus on the goals (products), not the means (processes) to achieve them. This having been said, there appears to be much work in progress in Europe on high-aspect-ratio devices through processes such as deep reactive ion etching (DRIE) and LIGA-like processes.

* Silicon micromachining is only one of the tools employed in the quest for miniaturization. Our team heard of work on polymers, glass, even metals. CMOS-based research centers (such as IMEC, the University of Delft, or Siemens/Infineon) are naturally approaching the microsystems field from the point of view of enhancing the integrated circuit capabilities through back-end micromachining and forming an integrated, low-cost device. However, the majority of the institutions visited which do not have the silicon CMOS focus place less emphasis on silicon integration, as they are targeting small- to medium-volume applications, such as medical applications, with less restrictive cost constraints.In summary, the focus in the European microsystems community is on device and system miniaturization using the processes and materials that fulfill particular application requirements. The device domains receiving the greatest attention in Europe appear to be those that are relatively simple, and that have limited requirements for movement. The push is toward simple miniaturized devices which provide incremental performance advantages over their traditional counterparts, not revolutionary new concepts and break-through applications. There is a large amount of work going on in the micro-fluidics area with medical, biological, and chemical applications targeted as the next area where microsystems will move into commercial markets.
Nanyoly Mendez

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